var minute = 1000 * 60;
var hour = minute * 60;
var day = hour * 24;
var halfamonth = day * 15;
var month = day * 30;

//这是第一次打开页面时调用
function formatDate(dateTimeStamp) {

    if (dateTimeStamp == undefined) {

        return "";
    } else {
        dateTimeStamp = dateTimeStamp.replace(/\-/g, "/");

        var sTime = new Date(dateTimeStamp).getTime();//把时间pretime的值转为时间戳

        var now = new Date().getTime();//获取当前时间的时间戳

        var diffValue = now - sTime;

        if (diffValue < 0) {
            return dateTimeStamp;
        }

        var monthC = diffValue / month;
        var weekC = diffValue / (7 * day);
        var dayC = diffValue / day;
        var hourC = diffValue / hour;
        var minC = diffValue / minute;
        if (monthC >= 12) {
            return dateTimeStamp;
        }
        if (monthC >= 1) {
            return parseInt(monthC) + "个月前";
        }
        else if (weekC >= 1) {
            return parseInt(weekC) + "周前";
        }
        else if (dayC >= 1) {
            return parseInt(dayC) + "天前";
        }
        else if (hourC >= 1) {
            return parseInt(hourC) + "个小时前";
        }
        else if (minC >= 1) {
            return parseInt(minC) + "分钟前";
        } else {
            return "刚刚";
        }
    }

}